The preferred way of removing the Swfdec is to open up the "Synaptic Package Manager", search for "Swfdec" and then remove "libswfdec-x.x-xx" and "swfdec-mozilla".
Now search for "flashplugin-nonfree" and install it. This should get flash running using the Adobe Shockwave flash plugin.
If the above did not work, try this:
- Write "about:config" in address bar and click enter.
- Change "plugin.expose_full_path" to "true".
- Write "about:plugins" in address bar and click enter.
- In the "Shockwave Flash" part of the page you should now be able to see the full path name to the "libswfdecmozilla.so" file.
- Remove the "libswfdecmozilla.so" file from the path specified.
- Remove the plugin database file. On my computer, it's located at: "~/.mozilla/firefox/z3tjq6i8.default/pluginreg.dat"
- Now start firefox and browse to a location that contains flash files. I had problems playing the live feeds from here (click so why not try this to verify the installation.